Air-pressure indicator for pneumatic tires.



0. 0. BRENNER. AIR PRESSURE INDICATOR FOR PNEUMATIC TIRES.

APPLICATION FILED JUNE 2,1914.

1,119,236, Patented Dec. 1,1914. EQZ I525 F115 \i 1 a Q E E t 5 3* \i' i E Q i g s 1 I v t f 9 f 44 f 1X l- J @A 5 WITNESSES INVENT R W C a 1 0, F mQr "UNITED 'sTAfrEs PATENT OFFICE.

CARL 0. BRENNER, 0F DESCANSO, CALIFOBNIP AIR-PRESSURE INDICATOR eon PNEUMATIC TIRES.

Application filed June 2, 1914.

one piece a housing for the interior mem-.

hers of the indicator and an ordinary air valve. so that but one hole will be necessary in the rim of the wheel on which the tire is used; and to provide the indicator therein. I

l attain these and other objects by the device illustrated in the accompanying drawings which are drawn to an enlarged scale with the exception of Figure 8.

Similar reference charactersrefer to like parts throughout the several views.

Fig. 1 is an elevation of a cross section through the center of the housing 1; Fig. 2 a plan view of the housing 1 Fig. 3 an elevation of a on 5 section of the assembled device, through the center; Fig. 4 is a plan view of the device-assembled; Fig. 5 is a cross section of the assembled device taken on the line A-B of Fig. 4, showing the nipple l. elongated, the thimble 3 raised, and the spring .3 compressed; Fig. 6 is an elevation of the device at right angles to the preceding views, showing the housing threaded to hold the nut 6; Fig. 7 is a plan view of Fig. 6; the flange being partlyluoken away: Fig. 8 is a fragmentary view of the tire 1/ and the device secured thereon, partly in section, drawn to a reduced scale; 9- is an elevation of the circular thimble 3; Fig. 10 is an elevation of the elastic nipple 4.

'i'he parts are assembled as follows: An ordinary air valve is disposed within the recess d in the housing 1; a spring 2 is dispos'ed in the upper end of the chamber a, a graduated thimble 3 is disposed beneath said sprin a rubbc ni pie 4 is disposed beneath said thimble an secured air tight at the bottom by a plug 5 which has a small hole in the center thereof.

Specification of Letteni Patent.

Serial No. 842,356.

When attached to a tire g as shown in F ig.-

8 the device is operated as follows:

The connection of an air pump is at tached to the tubular extension 0 on the pushes the'thimble upward against the spring 2 thereby compressing it as shown in Fig. 5. -..'I "l1e spring being of the proper resistance and the graduations on the thimble 3 being correspondingly calibrated, the reading is seen through the hole e. The readings are in pounds per square inch but any other convenient unit may be used.

By the use of my device the amount of pressure can be ascertained during the operation of inflation without removing the pump connection lYhen out on the road or at any other timc t he pressure can be ascertained by simply looking through the hole e. This device cannot be lost or mislaid since it a permanent fixture of the tire.

The maximum amount of service of a tire can only be secured by havin the proper amount of air in the tire at afi times. By the use of my device'this proper amount can he put into the tire without guess work and the decreased pressure due to leaking can be detected by looking-at the indicator. More than one hole in the rim of the wheel weakens it but by the use of my device only one hole is necessary in the rim or in the tire for both valve stem and indicator.

Having described my invention what I desire to secure by Letters Patent is- 1. A device of the class described comprising a cylinder having a longitudinally bored chamber therein; a spring disposed at the closed end thereof; an index member disposed against said spring; a plunger member disposed against said index member; an aperture in the side of said cylinder opening on said index member; a plug having an aperture therein, disposed at the mouth of said chamber: a longitudinal hole extendin through said cylinder parallel with sai chamber; and an air valve disposed at the upper end of said hole for the purposes specified.

2. A device of the class described com- Patented-Dec. 1, 1914.

prisin a cylinder having an outwardly extende flange at the base thereof; a longitudinally bored chamber having an opening in the side thereof, a spring dis osed at the 5 upper end thereof, a tube clos at the upper end having the lower edge'firmly secured y a threaded plug; a graduated thimble disposed between said spring and said elastic tube; a hole parallel to said chamber ex tending throu b said cylinder eccentrically 10 therewith; an an air valve disposed within said hole; substantially asdescribed and for the purposes set forth. v r

CARL 0.. BRENNER.

Witnesses:

H. H. HIMEBAUGH, JOEL C. JOHNSON. 

